1. Field of the Invention
The present invention relates to a light modulator utilizing the variation in the orientation of the vibration plane of an irregular ferroelectric crystal accompanying the polarization reversal thereof.
2. Description of the Prior Art
There are various conventional optical switching elements such as ammonium dihydrogen phosphate (hereinafter referred to as ADP) employing an electrooptical effect and Kerr cells employing birefringence caused when a substance such as nitrobenzene is placed in an electric field. All of these elements are such that the intensity of light transmitted through these elements is controlled by placing the elements between two polarizers the vibration planes of which are orthogonal and applying thereto an electric field. In such elements
1. The quantity of light transmitted therethrough is proportional to the applied field. A high voltage is necessary for intensifying the brightness of the transmitted light.
2. Since the quantity of transmitted light is proportional to the applied field, light is not transmitted when the applied voltage is reduced to zero, that is, these optical elements have no memory function. Therefore, in order to maintain the brightness at a constant value, it is necessary to keep the elements impressed with a voltage corresponding thereto.